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Doc_J
09-09-2016, 03:14 AM
Just held a gorgeous, two year old uke made of Ziricote, that I was shocked to see several cracks along its back. There were at least 4 visible cracks that could be felt as well as seen. Crack lengths were 7",5",4",1" long, along the length, with the grain. I spy another 1 or 2 that are shorter or just starting. I've attached a pic.

I'm certain these were not there when it was built. The owner bought it new and has had the uke for two years in Florida. So it probably didn't Have a lack of humidity, actually it may have had too much. But, I don't know it's history. Maybe the wood wasn't completely dry when it was used. I don't know what the problem was and can only speculate. Interestingly, the spruce top on this uke shows no sign of any cracks. So, maybe the problem was Ziricote?

This is got me wondering if there are some woods such as Ziricote that may be more susceptible to cracking over time? I suppose it might have something to do with the figure in some woods, or their brittleness. Are there woods that luthiers do not prefer to use for this reason?

http://forum.ukuleleunderground.com/attachment.php?attachmentid=94065&d=1473424267
http://forum.ukuleleunderground.com/attachment.php?attachmentid=94086&d=1473500160

Andyk
09-09-2016, 04:32 AM
my first thought looking at your photo was it looks like someone has sat on it or similar. However I'll play the "I'm no expert" card and see what the clever people say. :)

Doc_J
09-09-2016, 05:32 AM
my first thought looking at your photo was it looks like someone has sat on it or similar. However I'll play the "I'm no expert" card and see what the clever people say. :)

That thought hadn't struck me. The owner said it was in "pristine condition". So, my mind didn't even go that direction. Also the top and sides were without damage. The cracks don't show any light through them. There's no buzzes or unwanted vibration, the uke sounds great.

resoman
09-09-2016, 05:44 AM
I've seen Bocote and Ziricote crack like that along with Brazilian rosewood. I have a dobro that is Brazilian back and sides and it is trying to crack. I've seen several Brazilian dobros and guitars that were cracked but this had no effect on tone. The stuff is just brittle and I've never bent it, I have some but am afraid to LOL, but I understand it is scary brittle to bend. I'm sure there are other woods that I am not familiar with that are along the same lines.

Michael N.
09-09-2016, 06:54 AM
Hard to say if they are cracks or not. Hardly definitive going by a photo. The lower one doesn't seem to be following any grain line and it looks a little well behaved. It could equally be a long scratch or a finish crack. If the Uke was finished with Nitro I'd be thinking finish.
Some idiot has also scribbled green marker pen all over the back of that uke. It obviously hasn't had a pleasant life.

hammer40
09-09-2016, 06:59 AM
I have read that there are indeed some woods where it is a matter of when, not if, they will devolope cracks.

Beau Hannam Ukuleles
09-09-2016, 07:08 AM
Brazilian rosewood, and Ziricote are the notorious ones.

When I receive a set of those woods and see a crack, i don't even blink.

Snakewood is cracky but that is more for decorative things, rarely back/sides.

Kekani
09-09-2016, 07:16 AM
I stay away from anything spalted.

Pete Howlett
09-09-2016, 07:36 AM
All of 'em. They are treacherous and expose themselves either when you have got the finish on or when the owner leaves their uke in a hot car!

Red Cliff
09-09-2016, 07:39 AM
On almost all of the classical and acoustic guitar forums Ziricote is affectionately known as 'Mexican Crackwood'. I guess that is for a reason.;)

Matt Clara
09-09-2016, 09:31 AM
Just to add to the list of woods that crack, last winter I was working on a separate project (not uke related) and was thinking of using zebrawood. When I went to the lumber mill near me that carries such exotics, I quickly changed my mind, as I saw lots of cracks in the ends of the boards they had in stock. Not all of them, but enough to make me shy away. A couple of months later someone was showing me their zebrawood ukulele (Kala, as I recall). Two cracks in the back of it, one wide open. Owner said it had never been dropped or abused.

Beau Hannam Ukuleles
09-09-2016, 12:03 PM
When i use BRW or ziricote, after binding I flood the hell out of them with thin ca glue. I ca the inside of the backs before I glue the tops on too.

This want help against crack that develop through neglect (Nothing will), but it will reveal and minimize/stop invisible hidden cracks from getting worse.

Even great quality BRW cracks

Doc_J
09-09-2016, 03:20 PM
Maybe a CA pore fill has some crack abatement side benefits?

sequoia
09-09-2016, 08:25 PM
Whoa, whoa... I have been working with ziricote for a couple of months now so I can say I have a little experience with it and I love this wood. First of all this wood does not crack, it "checks" in that it separates at the grain when it drys. Any wood that checks is just drying out. All woods check to some extent. The problem with ziricote, as I understand it, is that it tends to check in the the early stages of drying. With properly seasoned ziricote, I have not seen any evidence of checking or cracking. What you are seeing is green ziricote that is probably improbably seasoned. It sands and mills very politely. A little fibrous like these tropical hardwods can be, but it reminds me of koa in a way. I love this wood. But who can afford the nice stuff. Not me.

94085

Masonguitars
09-10-2016, 06:38 AM
I've used Ziricote on one instrument. After pore filling and brushing on a few base coats of shellac on the body, I put it aside to work on a different instrument. When I came back to it a few weeks later, the back had split from stem to stern, clearly in reaction to a humidity change which happens frequently in the Midwest. I've had occasional small cracks develop, but nothing like this. Since it was too big to repair, I took the back off put a different Ziricote back on. It's been six or seven months now, and no problem. I love the look, but I will think twice before I use Ziricote again.

kohanmike
09-10-2016, 07:41 AM
I had a Lanikai solid top monkey pod tenor cutaway that developed a crack when I was in the process of making a bookshelf into a humidor. It looked like it was at the seem of the bookmatch so I don't know how much that counts here. As I was procrastinating, the weather in Los Angeles got very dry and one morning I went to the shelf where I was temporarily storing my ukes and discovered the crack, which prompted me to quickly finish the shelf. I also had a Lanikai zebra wood, both had very strong grain patterns. I gifted the monkey pod to a young cousin, who was very happy, as was his father who didn't have to buy a uke.

http://www.kohanmike.com/uploads/Monkeypod crack.jpg

sequoia
09-10-2016, 06:53 PM
When I came back to it a few weeks later, the back had split from stem to stern,

Interesting. Was it along the joint seam or a grain line I wonder. It is kind of oily like rosewood and gluing can be problematic. I've been trying to wipe joint faces with alcohol (when I rememeber) Anyway, I think anytime we mess with these highly figured or spalted woods, we are probably asking for trouble. Just the nature of the beasts perhaps. So far so good with my ziricote. Oh and by the way, filling my ziricote has been... challenging. It doesn't so much have pores as crevasses.

Masonguitars
09-11-2016, 05:58 AM
It split basically with the grain, but a series of individual splits close to each other running the length of the back. I did not find Ziricote to be oily like Cocobolo, but it did stain my shellac pad until it was sealed. If the staining was oil, it was not a problem for gluing.

hawaii 50
09-11-2016, 08:02 AM
That thought hadn't struck me. The owner said it was in "pristine condition". So, my mind didn't even go that direction. Also the top and sides were without damage. The cracks don't show any light through them. There's no buzzes or unwanted vibration, the uke sounds great.

the sad part is that the seller told you the uke was in "pristine condition" because I am pretty sure many woods do crack.....kind of looks to me someone sat on it are you returning it? maybe you should warn uke buyers who the seller is in a private message....my 2 cents

mm stan
09-11-2016, 12:53 PM
I have a zircote, tenor 3 and half years old and no cracks
The uke was not properly humidified.
I hope you can return it, the uke is probally worth 200 dollars

Doc_J
09-12-2016, 06:52 AM
Thanks Len and Stan. Yes, this particular uke is being returned to it's original owner.

It does seem some woods are more prone to cracking, and ziricote appears to be such a wood. I didn't mean to imply that ziricote will crack, but may be more likely to crack than some other tone hardwoods when stressed from humidity, temperature, etc. Brazilian Rosewood & Bocote also appear to be woods with a higher potential of cracking.

From the discussion in this thread, there are some steps one can take to mitigate the possibility of cracking (proper drying/seasoning, CA application, proper humidity, ...).

mm stan
09-12-2016, 04:22 PM
Thanks Len and Stan. Yes, this particular uke is being returned to it's original owner.

It does seem some woods are more prone to cracking, and ziricote appears to be such a wood. I didn't mean to imply that ziricote will crack, but may be more likely to crack than some other tone hardwoods when stressed from humidity, temperature, etc. Brazilian Rosewood & Bocote also appear to be woods with a higher potential of cracking.

From the discussion in this thread, there are some steps one can take to mitigate the possibility of cracking (proper drying/seasoning, CA application, proper humidity, ...).

Also Hodge, if it is made in a climate controlled workshop...and the wood itself, meaning not only type but
Also this particular piece of wood from a part if the tree which has weakness in the grain structure due to many factors

tenor madness
09-13-2016, 01:37 PM
I recall reading a tab in here where a least a couple of luthiers said Redwood tops are more likely than most other top woods to crack (not saying they are likely to, just a little less stable than other top woods).

Beau Hannam Ukuleles
09-13-2016, 06:23 PM
I recall reading a tab in here where a least a couple of luthiers said Redwood tops are more likely than most other top woods to crack (not saying they are likely to, just a little less stable than other top woods).

Redwood is to brittle what cedar is to soft. I wouldn't say redwood was a crack prone wood, but like cedar you just need to take some extra care handling it.

mm stan
09-15-2016, 01:19 AM
I recall reading a tab in here where a least a couple of luthiers said Redwood tops are more likely than most other top woods to crack (not saying they are likely to, just a little less stable than other top woods).

I have not had any problems with my redwood tops nor have I seen any yet, whether it's my luck or
The chosen pieces by my luthiers